Growth of fungi, such as certain types of black or gray molds in residential and commercial buildings, can produce significant health hazards to human occupants of such buildings. For example, the black molds known as Stachybotrys and Memnoniella are types that are known to produce mycotoxins which are hazardous to human health when exposure is encountered. These mold types typically occur on repeatedly wetted materials that contain cellulose, for example, including interior wall paneling, such as gypsumboard, and other materials used in residential and commercial buildings including cardboard, ceiling tiles, cellulose insulation, wood, etc.
Fungi, primarily Aureobasidium pullulans, are responsible for the mildew growth seen on the exterior painted surfaces of houses, particularly in warm, damp climates. Algae, primarily Chlorophyta and Myxophyceae also appear on such painted surfaces. Fungi, primarily Aspergillus niger, are responsible for the mildew growth seen on hard indoor surfaces, such as bathroom tile and grout. Removal of such algae and fungi from hard surfaces, particularly painted surfaces, is a difficult problem. If the fungi and algae are not completely removed from painted surfaces they could reappear at a rate faster than that at which they were observed growing originally. Detergent compositions, as disclosed in U.S. Pat. Nos. 4,097,395 and 4,164,477, are known for cleaning hard surfaces. These compositions contain a fungicide, detergent and organic acid as well as components that function as degreasants, wetting agents, sequestering agent, penetrants and the like. The detergent compositions are diluted with a bleach just prior to application.
There are several sources of moisture which can accelerate and promote the growth of gray and black molds including the types mentioned above. Water piping extending through plumbing chases and piping extending through voids or spaces in interior walls of residential and commercial buildings can produce minute leaks sufficient to wet adjacent materials and promote the growth of mold. Leakage from the exterior of a building into various parts of the building, which goes undetected, can also wet the surfaces of various materials which will promote the growth of toxic molds. Still further, condensation, from time to time, on the surfaces of plumbing piping, air conditioning ducts, refrigerant conduits and other structures is also a source of moisture which can result in the growth of molds in unseen spaces, such as the interior wall spaces of buildings, among other locations, all of which are a source of mold contamination and exposure to humans.
The growth of mold in interior wall spaces in residential and commercial buildings is particularly difficult to detect and difficult to eradicate by conventional methods. Since the interior wall spaces have been covered with various types of wall paneling, the growth of mold goes undetected and, when detected, is difficult to treat without major renovation of the building. Accordingly, there has been a longstanding need for the development of mold and other pest prevention systems and treatment methods which can eliminate toxic molds, in particular, from various places within a residential or commercial building, including interior wall spaces, plumbing chases, and virtually any portion of a building structural feature which is likely to be exposed to moisture, repeatedly, during the life of the building. It is to these ends that the system and methods of the present invention have been developed. A broad range of organic molecules have been found to have fungicidal and bactericidal properties and are effectively used for plant disease control. However, many of the currently used pesticides pose a high risk to human health and the environment and are not biodegradable. Since the establishment of the Environmental Protection Act in 1972 there has been an increased concern over the use of toxic chemicals for plant disease control and the dangerous residual potential these toxic products represent. The United States Congress disclosed its concerns with those products with the passage of the Food Quality Protection Act in August, 1996 which requires the U.S. EPA to reassess each existing pesticide by 2006. Because of toxicity concerns, to reduce residues on crops, fruits and vegetables, the application of pesticides shortly before harvest must usually be avoided. Additionally, because of concerns regarding the health of workers, entry into fields or greenhouses shortly after pesticide application is usually prohibited.
Therefore, there is a real need to provide more biocompatible fungicides and bactericides which are, by definition, safe in the environment, non-toxic to humans and animals, and which are rapidly biodegradable.